Placement variability in intraoral pressure
Kim A. Wilcox, J. Anthony Seikel, David G. Drumright · The Journal of the Acoustical Society of America · 1990
A traditional understanding of the speech waveform of vowels assumes that the extraoral acoustic output is the product of the combination of a glottal source and the filter function of the oral tract. This approach, while functional, does not assess point differences of the acoustic signal within the oral tract. The present study compares the output waveform with differences in intraoral pressure at specific locations within the oral cavity. A probe microphone system was developed to measure the localized signal at 68 points within the oral cavity. The present data show that the third formant varies most widely, with diminishing differences as the probe moved anteriorally. Observed variations in F3 include (1) additional resonant lobes, (2) frequency shifts, and (3) complete formant ablation. While F1 and F2 are relatively stable, the strength of component resonant lobes is shown to vary as a function of measurement location. Results will be displayed relative to an oral-cavity map. [Work supported by Univ. of Kansas, General Research Fund, and USDE.]